Antifouling pipe line enamel



Patented Dec. 25, 1951 AN TIFOULING PIPE LINE ENAMEL August Holmes, Cranford, N. J., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application September 4,1948,

Serial No. 47,941

2 Claims.

1 This invention relates to improvements in protective coating compositions and to methods of protecting surfaces against corrosion, and more particularly to the use of asphalts derived It is the object of this invention to produce an improved bituminous enamel which will be particularly suited for marine service in that its protective function will not be appreciably from petroleum hydrocarbons for coating com- 5 affected by the actionoi tropica marine ow positions. The'coating composition of the preseven f under the Surface the Water for ent invention is particularly adapted for use in long perlPds of i salt and brackish tropical Waters Accordmgto this invention, the improved pipe A petroleum crude oil may be distilled to reeflamel is obtfiined by incorporating into P m the more Volatile fractions and produce a bitumen of suitable consistency and properties, more or less fluid residue which remains in the certain toxic materials which inhibit the attack still. This asphaltic residue has various uses of terf3dS'barp:ac1es P sponges These tome Such as a bonding agent or by additional prom materials are inorganic compounds of heavy essing converted into coating composi which metals selected from the class consisting of on application to metallic surfaces prevent corq barmm which compounds f rosion and rusting. Another asphaltic material 9 m the rangeof to .001% by weight which can be used for corrosion prevention is m Salt W Particularly des.lrable compounds the asphaltic residue obtained by distillation of banum i ig and i ig QE 1 the heavy residual oils resulting from breaking n g p ifii e tumen S down under heat and pressure of petroleum heated un 11 it s su cicntly fluid but 1n no case distiuates should the temperature be higher than 50 F. Other asphalts are found naturally in lakes below flash point of the u A mineral such as in Trinidad and in veins from which finer 1s t-hen added and thoroughly mixed the must be mined Such as flsonite lance after which the toxic agent is similarly iny g g corporated. pitch and grahamite. Although some of these A number of coating compositions were natural, products are admirably suited for the pared employing various toxic materia1s The tttiifitii astral; imitless; i0 an a s ee 5 of me a. e pipes and the g geg gg g ggg g i Ji 5 222 metal sheets were then immersed in the water J 0 p of Lake Maricaibo, Venezuela, for 20 months. i je i re already in use a number of pipe 8 enamel 1 fifi i by fi esameon e ew'entecase e enamels satisfactory for the protection of pipes sheets or paddlespdgpping processes wereousted against corrosion and rusting when the pipe lines The a l wer prepared by mixing 60% 2iotiii ttiffiiifi difoiiti uitii Sittiii it??? f and adding were 0 y vo ume o 0 sons. The filler conwhen such construction materials are submerged i iged f 10 rts ie with 30 parts of slate in sea water and submitted to att k by t r flour. At the end or 20 months test results were barnacles, sponges or other forms of marine observed which are tabulated in the following growth. table.

8 m 1 Pipe Test Paddle Test NJ? e Toxic Compounds Sponge Tcredo Blisters Sponge Teredo Blisters C gger Naphthenate 1% 8 8 8 1% 1C) 3. Copper Naphthenatc 2%. B C A D C A Octadecylamine 1% A C C D C C Octadecylamiue 2%.... C D C D E C Petroleum Phenols 1%. A C B C C A Petroleum Phenols 2% D C C B B B Ammoniated Mercuric Chloride 1% D C A B B B Ammoniated Mercuric Chloride 2%. C A C C C C Chlorinated Naphthalene 1% A A C A B B Chlorinated Naphthalene 2? A C C E B B Barium Carbonate 1% A A E E B B Barium Carbonate 2% B A B B A A Antimony Oxide 1%-. B A A B B Antimony Oxide 2% B B B A A A-Coatlng apparently not afiected.

C-Coating moderately affected.

As pointed out heretofore the poison is selected from the class of inorganic compounds of heavy metals selected from the class consisting of antimony and barium. It is essential that these compounds have a very slight water solubility preferably in the range from .001 to .02% by Weight in salt water. In general the material should have a molecular weight of about 120 and higher. As can be observed from the test, barium carbonate and antimony oxide are outstandingly effective as compared with various other types of poisons.

The bituminous material may be derived from petroleum hydrocarbon by the distillation of coal, shale and the like to secure distillation residues. Suitable bituminous materials comprise petroleum tars and coaltars having ring and ball softening points between 145 F. and 250 F. These can be obtained by the straight reduction of crude petroleum products, or of the tars obtained from cracking petroleum products from the oxidation of straight reduced products from petroleum or from the petroleum tar and from residues derived from the distillation of coal, shale or other organic materials.

A preferred composition comprises an oxidized asphalt in combination with slate flour and mica. The oxidized asphalt is prepared by blowing air through an asphalt having a softening point in the range from about 60 F. to 100 F. This material is heatedto a; temperature within the range from about 350 1 to 550 F. but not above the flash point of the feed material. The air blowing treatment is continued until the desired softening point of the asphalt is raised to about 200 F; to 250 F.

The concentration of the bituminous material in the coating composition may vary appreciably. In. general it is preferred that the concentration of the bituminous material be in the range from about 40-70% and the fillerpresent in the concentration of about 60-30%. Particularly effective compositions'are secured when the concentration of bituminous material is in the range from about -65%. The filler preferably comprises a mixture of slate flour and mica where approximately 2 to 4 parts of slate flour are employed per part of mica. The amount of poison employed should be in the range from about 0.5% to 5%. As indicated by the test data, efiective concentrations are in the range from 1% to 2%.

Having described the invention, it is claimed:

1. An improved coating material suitable for employment in tropical waters which comprises from 0.5 to 5% of antimony oxide and from about 40 to of a bituminous material having a softening point in the range from 200 to 250 F. and a filler.

2. Composition as defined by claim 1 wherein the bituminous material comprises an oxidized asphalt prepared by air-blowing an asphalt hav ing a softening point in the range from about 60 to F.

AUGUST HOLMES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,096,876 Bitzer Oct. 26, 1937 2,158,771 Beckwith May 16, 1939 2,506,283 Smith et a1. May 2, 1950 FOREIGN PATENTS Number Country Date 169,758 Great Britain Oct. 3, 1921 473,184 Great Britain Oct. 1, 1937 480,049 Great Britain Feb. 16, 1938 OTHER REFERENCES Circular No. 259, Scientific Sec., Paint Mfg. Assoc. of U. S., January 1926, pp. 240-241. 

1. AN IMPROVED COATING MATERIAL SUITABLE FOR EMPOLYMENT IN TROPICAL WATERS WHICH COMPRISES FROM 0.5 TO 5% OF ANTIMONY OXIDE AND FROM ABOUT 40 TO 70% OF A BITUMINOUS MATERIAL HAVING A SOFTENING POINT IN THE RANGE FROM 200 TO 250* F. AND A FILLER. 